Table of Contents

Lisa

is a Display Controller Integrated Circuit. offering considerable advantages to the Amiga product line, both new features and higher performance.

The basic function of Lisa is to accept bitplane data and sprite data from chip ram, and serialize and prioritize them to provide a set of signals suitable for input to a video DAC. Lisa also provides mouse/joystick circuitry and genlock support.

Lisa (von HP)

New features for Lisa (as compared to ECS Denise):

32 bit wide data bus supports input of 32-bit wide bitplane data and allows doubling of memory bandwidth. Additional doubling of bandwidth can be achieved by using Fast Page Mode Ram. The same bandwidth enhancements are available for sprites. Also the maximum number of bitplanes useable in all modes was increased to eight (8).

The Color Palette has been expanded to 256 colors deep and 25 bits wide(8 RED,8 GREEN,8 BLUE,1 GENLOCK). This permits display of 256 simultaneous colors in all resolutions. A palette of 16,777,220 colors is available in all resolutions.

28Mhz clock input allows for cleaner definition of HIRES and SHRES pixels. ALICE's clock generator is synchronized by means of LISA's 14MHz and SCLK outputs. Genlock XCLK and XCLKEN* pins have been eliminated (external MUX is now required) .

A new register bit allows sprites to appear in the screen border regions.

A bitplane mask field of 8 bits allows an address offset into the color palette. Two 4-bit mask fields do the same for odd and even sprites.

In Dual Playfield modes, 2 4~bitplane playfields are now possible in all resolutions.

Two extra high-order playfield scroll bits allow seamless scrolling of up to 64 bit wide bitplanes in all resolutions. Resolution of bitplane scroll, display window, and horizontal sprite position has been improved to 3Sns in all resolutions.

A new 8 bitplane HAM mode has been created, 6 for colors and 2 for control bits. Both HAM modes are available in all resolutions (not just LORES as before).

A RST input pin has been added, which resets all the bits contained in registers that were new for ECS or LISA: BPLCON3, BPLCON4, CLXCON2, DIWHIGH, FMODE.